Telegraph-distortion-measuring machine



Aug. 31 1926.

J. HERMAN l TELEGRAPH DlSTORTION MEASURING MACHINE Filed May 24, 1924 Patented Aug. 3l, 1926.

nutren lil JOSEPH HER-MAN, OE NEW YORK, N. Y., ASSIGNOR TO AMERICAN TELEPHONE AND TELEGRAPH COMANY, A CORPORATON MEXX] YORK.

TELEGRAPH-DSTORTION-MEASURING MAGHINE.

Application filed May 24,

This invention relates to means for measuring telegraph distortion and particularly to a system in which the length of each unit, mark or space transmitted over a telegraph circuit may be measured and recorded.

Hereto'fore, in the measurement of telegraph distortion it has been customary to use a bridge, such, tor example, as that disclosed in the patent to Nyquist, No. 1,435,328, which issued November 14, 1922. Bridges of that type or ont any type heretofore used measure only the average distortion ot the transmitted signal and are oi' little use where the distortions are largely variable. Since the variable distortions determine to a considerable extent the grade ot telegraph service which can be given overa circuit, it is vdesirable to have a simple means 'for measuring such variable distortion.

It is the object of this invention to provide a distortion measuring device which will indicate the maximum distortion prevailing in any telegraph system and the frequency with which a specified amount of distortion is exceeded.

This invention will be clearly .understood from the following description when read in connection with the attached drawing, showing schematicallyT one form of embodiment oLt the invention.

1n the drawing, a telegraph circuit 1 is connected with the winding 2 oi' the receiving relay 3. The armature 4 of this relay is adapted to move between marking and spacing contacts with which are connected thenegative and positive batteriesV 5 and 6 respectively. The armature ol' this relay is connected with the arm 7 of the distributor face 8, which is somewhat similar to that used in the present start-stop printing telegraph system. Connected between the armature 4 and the arm 7 is a condenser 9, the function of which will be stated hereinafter. This distributor face comprises a plurality ot segments, equal in size. The segments to the right ot the division marked zero are designated minus 1 to 10 and those to the lett of the zero Vdividing lineare designated plus l to 10. As will appear hereinafter, a greater number otsegments, similar to those designated 1 to 10, might be included it desired. vThe segment designate-d 11, which constitutes the rest of the circumterence oit the distributor tace, is connected with the winding et the magnet which.

1924. Serial No. ?15,7G6.

controls the release of the arm 7. Segment minus 1 is connected by conductor 13 with the winding of relay 14. The left-hand contact of this relay is connected through the resistance 15 with the direct current source 16. rThe right-hand contact of relay 14 is connected with the winding ct' the message register `1'?, the armature ot which controls the register dials and also eliects the release of relay 14 whenever the armature of the message register closes its contact 18. The segment plus 1 is shown connected with a circuit similar to that justdescribed and in like manner each `of the plus and minus segments will be connected with circuits similar -to those shown connected with the segments plus 1 and minus 1.

The manner in which this circuit is operated in order to determine the magnitude of `distortion oi' a signal is as follows: At the outset, the circuit is calibrated by applying to the winding 2 an undistorted signal suoli, tor example, as the E signal, which consists of a single dot and a much longer space. This is applied by means of a source 19 connected with the winding 2 through the switch 20. The speed oit the arm 7 oit the distributor is then adjusted so that the time required to make halt a revolution is equalto the dot length to be measured. ln other words, the brush speed of the distributor in cycles per second is equal to the signaling speed in cycles per second. y

During the spacing interval of the E signal applied to the winding 2by the source 19, the armature 4 remains upon its spacing `contact and the condenser 9 is charged positively by the flow of current from the source 6, through the spacing Contact, the condenser, the arm 7 and its associated brush, and the winding of the magnet 12. `When the marking impulse is applied by the source 19 to the winding 2, the armature 4 moves to its marking contact, thereby connecting the negative battery 5 with the circuit containing the condenser 9. rlhe resultant current causes the magnet 12 to release the brush arm 7.

This arm will then continue to travel over the segments ot the distributor face in the direction represented by the arrow. Since the speed otrotation cgt this arm has been vadjusted with reifernce to the length of the dot ot the impressed signal, the brush will be resting upon one of the segments in the viciiit'y the zero dividing line the end. el

the marking impulse.- At this time, that is to say, when the armaturev 4 moves to its spacing contact an impulse of current will be transmitted through the condenser 9 and the arm 7 and its associated brush to the circuit connected `with one ofthe segments.

Let us assume that .this is segment minus 1. Accordingly, relay 14u/ill be energizedl and through its right-hand-contact it will energize the Winding of the message register 17 and cause the recording upon the dial ot' that register an indication ot such operati-on. The relay 14 would also be locked up by current flow-ing from the source 16 through the lett-liand contact of the said relay. However, as soonas the message register 17 operates the source 1G is sli-unted throughthe contact' 18, and the relay 14 is released for further use. The releasing ,of relay 14 also releases Athe messageregister. v

If the brush of the arm 7 rests upon the segment plus 1 at the instant the armature 4 moved .to its spacing contact, the relay 14 would be operated, which would, in turn', operate the message register 17 and cause the registration of such 'operation upon the dial thereof. Since the signal applied by the source 19 to the Winding 2 was a perfect signal, that is to say, it was undistorted in any Way, as might have been the case if it' had been received over the circuit 1, the arin of the distributor should havev reached the dividing line zero at theinstant of termination of the dot impulse, that is to say, at the instant the armature 4'moved back to its spacing contact. To complete the calibration of the set prepara-tory to measuring the signals received over the line 1, the face of the distributor 8 is oriented so that the brush oia the arm 7 `Will reach tliejzero dividing line .at the termination of the dot impulse. This condition can be determined by Watching the operationot the message registers connected with the' segments plus l and minus 1 during the receipts of a number of signals from the source 19,

lilith the set thus adjusted, the apparatus is ready to measuredistortions received over the line circuit 1; The cali-brating source 19 would' be disconnected by opening the switch 20, The signal to be measured is then transmitted over the line 1 inthe usual manner androperates the relay 3, causing the armature 4 to move between i-ts marking and spacingv contacts. At the beginning of reach marking or spacing impulse.thebrush-arin 7 is released; At t-lie end of each impulse-a record is made on'the message register corresponding to the vparticular dot length. f In this Way the length oiiy each' impulse is-recorded automatically and the value and the number' of distortions occurringon the telegraph circuit in acertain length of time may be obtained from the readings of the various message registers. It should be yunderstood that the arm 7 does not rotate continuously but is held by the pau/121 atter it reaches this point after each revolution until a releasing impulse is applied to ythe magnet 12 throughthe condenser 9. 4

In the arrangement shown in the drawing, .ten small segments are indicated on each side of the -zero dividing line. Each of these groups of segments constitutes a quadrant of the distributor face or one-halta dot length and each' segmentconstitutestiveper cent of a dot length. Consequently, segment minus land'its associated circuit registers all distortions from zero to minus five percent, and segment minus 2 from minus five percent to minus .ten per cent and so on'up-,to minus 50 :per cent.y These negative segments could be continued through'another 'quadrant so as to measure negative distortions of 50 to 100 per cent andl in similar manner positive segments could be added to measure distortions from plus`50 per cent ,to plus 100 per cent.

It will be seen, therefore, that by means ot ,the invention embodied inthe drawing and described hereinbetore the magnitude of distortion of one signal 0r succession of signaling impulses may registered and the condition of the 'line ymay be readily determined.

f 7h-ile this invention has 'been disclosed as-embodiedv in a; particular form it is to be understood that it is capable of embodiment in other forms Without departing from the spirit and scope of the appendedclaiins.

What is claimed is Y 1. In' a. telegraph distorting measuring machine, the combination with .a source of marking andspacing impulses of a relay responsive to the said impulses having an armature and sources of potential of opposite polarity connected with its contacts," a segmental rotarydistri'butor adjusted so. that thearm thereof WillY pass over a lixed num- Iber vofsegments While the armature of the saidv relay rests upon a certain contact, a condenser connected between said distributor arm andthe armature of the saidy relay,

vand registering devices, each connected with fa segment 'of the said, distributor to effectively Vrecord the magnitude of distortion-of the signa-l impulse actuating the said relay.

2; In a telegraph distortion measuring machine,.the combination with a source of marking and spacing impulses of a relay controlled thereby having an armature and sources of potentiall of opposite polarity vconnected with 'the .contacts'tli'ereoL 1a. ro-

tary distributor having an arm and a plu- `ralityof segments and adjusted so that the armA thereofrwill pass over a. predetermined number of segments when the impulse operating the said relay is undistorted, a condensver connectedfbetween said armV and said ar- 'ma-,turev adapted' to be charged in opposite senses by the source of markingand spacing impulses, and a plurality of measuring means individual to and connected with the various segments to register the degree of distortion of the impulses actuating the said relay.

3. In a telegraph distortion measuring machine, the combination with a. relay hav` ing a Winding connected therewith as a source of current impulses and having an armature adapted to move between contacts connected with sources of potential of opposite polarity, a rotary distributor having an arm and a plurality of segments, the said arm being connected With the armature or' the said relay, the connection including a condenser, a starting relay connected with one of the said segments having means to release the said arm, a plurality or' registering means connected with the said other segments, each registering means comprising a relay adapted to be energized by one of the sources connected with the said iirst relay, and a message register controlled by the relay connected with the said segments Whenever the brush of the said arm rests thereon.

4. In a telegraph distortion measuring machine, the combination with a source of telegraph signals, the length of Whose marking and spacing elements is to be measured, of a rotary distributor having a brush-arm and a plurality of segments, the said distributor being adjusted so that the arm Will travel over a predetermined number of segments during the continuance of an undistorted signal element, a plurality of electroresponsive devices, each individual to and connected with one of said segments, and a Acapacity coupling between said source of signals and said brush arm.

5. In a telegraph distortion measuring machine, the combination with a source of telegraph signals, the length of Whose marking or spacing impulses is to be measured, of a line relay having an armature and contacts, a source 'of marking and of spacing po` tential connected with said contacts, a rotary distributor having a brush arm and a plurality of segments, a condenser connected with said armature and said distributor arm, a releasing magnet connected with one of said segments operable Whenever the condenser is charged by its effective connection with one yot the contacts of said relay, thereby releasing said arm, and a plurality of registering devices each connected With one of said segments, each registering device being operable it the condenser is connected with the other of said contacts at the instant when the said brush arm is eectively connected with the segment to Which said registering device is attached.

In testimony whereof, I have signed my name to this specification this 19th day of May 1924.

JOSEPH HERMAN. 

